4C’s of Diamond

CARAT

Diamonds and other gemstones are weighed in metric carats: one carat is equal to 0.2 grams. A carat is further divided into 100 points. For example, a 25-point diamond weighs 0.25 carats or 0.05 grams. It is the internationally used unit to measure the weight of diamonds. In the diamond industry, weight is often measured to the hundred thousandths of a carat, and rounded to a hundredth of a carat.

COLOR

Diamond colour is all about what you cannot see. Diamonds are valued by how closely they approach colourlessness – the less the colour, the higher their value. (The exception to this is fancy-colour diamonds, such as pinks and blues, which lie outside this colour range.)

GIA’s colour grading scale for diamonds is the industry standard. The scale begins with the letter D, representing colourless, and continues with increasing presence of colour to the letter Z, or near-colourless. Each letter grade has a clearly defined range of colour appearance. Diamonds are colour-graded by comparing them to stones of known colour under controlled lighting and precise viewing conditions. Many of these colour distinctions are so subtle as to be invisible to the untrained eye. But these slight differences make a very big difference in diamond quality and price. It is extremely difficult to see the color differences within diamonds, but master stones help graders distinguish between one color and the next. Master stones are a set of real diamonds that display a range of known colors.

CLARITY

Diamond clarity refers to the absence of these inclusions and blemishes. Diamonds without these birthmarks are rare, and rarity affects a diamond’s value. Using the GIA International Diamond Grading System diamonds are assigned a clarity grade based on a scale that contains 11 grades. In determining a clarity grade, the GIA system considers the size, nature, position, colour or relief and quantity of clarity characteristics visible under 10× magnification.

CUT

Cut refers not to a diamond's shape but to a diamond's proportions, symmetry and polish. The beauty of a diamond depends more on cut than any other factor. Cut is the factor that fuels a diamond’s fire (the dispersion of light into the colours of the spectrum), sparkle (the flashes of light or sparkle, when a diamond is moved) and brilliance (the total light reflected from a diamond). The standard round brilliant is the shape used in most diamond jewellery. It is the work of a master cutter that allows the diamond to be cut in such a way as to permit the maximum amount of light to be reflected through the diamond, and that's a great reflection on you. It is the cut that enables a diamond to make the best use of light.

Cut depends on diamond proportions. Diamond proportion refers to the relationship between the size, shape, and angle of each facet of a diamond. A wide range of combinations are possible, ultimately determining the diamond's interaction with light.